Ph.D, but which field?

It's an important time for me, I need to decide what I want to do. I know I want to do a Ph.D (I have 1 year left of my Mphys degree in the UK) but I'm not sure about the fieldto specialise in. When I began university I was really set on doing a PhD in astrophysics.. But I've been put off by some of the astrophysics courses taught at my university (they were badly taught) and also the fact that astrophysicists seem to just sit at a computer and crunch numbers all day.

I'm also interested in Quantum information/Quantum computing as I'm really into computers (building/programming) and Quantum physics is one of my favourite areas of study.

I've looked at these two fields for sometime and my impression is that

Astrophysics - Not many jobs available, doesn't seem to be a great need for people in this field

Quantum computing - Has great potential but there aren't many universities who have groups that specialise in their development..

I'm also looking at attending a US university for my studies - for a change of environment, personal reasons and also the fact that there are many good schools.

My ultimate problem is deciding which field to focus on. Which field has a brighter future? Should I choose say 5 or 6 different fields at different universities and apply to them or should I just focus on one?

you have a masters degree and you are not sure - try to guess what people who are in college or have a bachelors think - we are not sure even more

if you are into physics then major in physics. if you want to get involved in QM/QC might as well go to grad school for EE

I am In college it's a 4 year course with the 4th year being the "masters" part. ZapperZ, thanks I'm reading those threads now but I'd rather have an opinion on the two specific fields them selves as opposed to a general discussion on employability etc.

Also is it possible to specialise in more than one field? for example I was researching into quantum computing and I came across John Preskill at Caltech and he specialises in quantum information thoery particle physics and cosmology.